Electrical heater



Nov. 18, 1941.

w. H. HEARD ELECTRICAL HEATER 2 Sheets-Sheet 1 Filed Nov. 25, 1946Inventor Wi/fihau Wear-0 Nov. 18, 1941. w. HEARD I 33,262,892

ELECTRICAL HEATER Filed Nov. 25, 1940 2 Sheets-Sheet 2 Jfifj- 6" l nventor By @Mm A iiorney Patented Nov. 18, 1941 UNITED STATES PATENTOFFICE ELECTRICAL HEATER William H. Heard, Portland, Oreg.

Application November 25, 1940, Serial No. 367,087

1 Claim.

My invention relates to improvements in electrical heaters, and theprimary object of my invention is to provide an arrangement of thischaracter wherein component parts of the heater are constructed to holdheat applied. thereto by the electrical heating element, so that duringthe course of a heating operation the energization of the heatingelement may be reduced or cut off, with corresponding savings in thecost and time, Without reduction of heating effect.

Another important object of my invention is to provide an electricalheating device particularly adaptable to replace gas, oil and coalheating elements in domestic and industrial furnaces and heating plants,with consequent savings in cost and operation and upkeep of suchfurnaces and heating plants.

Another important object of my invention is to provide an electricalheating arrangement of the character indicated which is automaticallythermostatically controlled so that a predetermined or desired adjustedtemperature may be uniformly maintained, and through whose use andoperation flues, combustion chambers, fire pots, and their attendant ashand products of combustion are eliminated and rendered unnecessary, withconsequent savings in expense of removal and disposal and reconditioningof the parts deteriorated and the presence thereof.

Other important objects and advantages of my invention will be apparentfrom a reading of the following description taken in connection with theappended drawings, wherein for purposes of illustration are shownpreferred embodiments of my invention.

In the drawings:

Figure 1 is a general side elevational view of the heating device perse.

Figure 2 is a transverse vertical sectional view taken through Figure 1,

Figure 3 is a horizontal sectional view taken through Figure 2 along theline 3-3 and looking downwardly in the direction of the arrows.

Figure 4 is a perspective view of one of the component sections ofeither the inner or the outer form,

Figure 5 is a bottom plan view of the sectional base, showing one of thecomponent sections separated from the others, and

Figure 6 is a general transverse vertical sectional view taken through aheating enclosure in which the heating device is the source of heat, andshowing sections of the outer form of the heating device removed, andwith thermostatic control arrangements incorporated.

Referring in detail to the drawings, the numeral 5 generally designatesthe device which is composed of a substantially circular base 6consisting of ninety degree segments 1 on the opposite ends of which aretongues and grooves 8 and 9, respectively, which mate with the tonguesand grooves of the adjacent segments to form a flat circular plate. Theapex portions of the segments 1 are cut off to provide an opening ID topass the thermostatic bulb ll shown in Figure 6. One of the segments 1is provided with a hole I 2 to pass the wires which lead from theopposite ends of the helical heating element or wire l3 which isspirally wound on the inner form to be described, the said wire passingthrough a suitable conduit to a thermostatic control box IS on theoutside of a furnace casing N5, the enclosure to be electrically heated.The thermostatic bulb II has its tube l1, like the conduit I4, passingthrough the side wall of the enclosure I6 to enter the control box I5.This control box may be of any suitable conventional type enablingpermanently fixing or temporarily adjusting the sensitivity of thethermostatic control for cutting in and cutting out the heating elementl3 with respect to a suitable source of current properly connected tothe control box as indicated by the numeral I8. The conduit [4 and thetube I! pass downwardly through an opening IS in a suitable support 20on which the base rests in proper relation to the side walls and the topof the enclosure l6 as exemplified in Figure 6.

An important advantage of having the base 6 and the inner and outerforms of the heating device in sectional construction is that thesections can be passed through the enclosure opening 2| and easilyassembled within the enclosure, whereas the assembled heating devicemight otherwise be too large to pass the opening 2|. The base 6 maysuitably rest on the support 20 in the enclosure to be heated, and besecured to the support in any suitable manner. The top of the base hasinner and outer circumferential grooves 22 and 23 concentric withrespect to the base for retention of the conforming annular ribs 24 and25 on the lower edges of the inner and outer forms to be described,whereby the inner and outer forms are assembled on the base and thesections of the base assembled with respect to each other so that thereis no heat lost through the joints thus effected.

The inner form which is shown and designated 26 consists of a hollowacorn shape formed of triangular segments 21 shown in Figure 4 of thedrawings and having on one side edge a taller so as to becircumferentially spaced at substantially equal distances from everypart of the inner form 26. The outer form isformed by triangularsections similar to the sections, 21..

and similarly provided with tongues an'd'grooves for assembly with thegroove 2 3".in,the base 6g and for interengagement with the tongues, andgrooves of the companion sections or segments, whereby all of; thesegments constituting the outer form.- areheldin assembled relation;

The outsideof theinner forrn26 is woundwith ahelix I3 ofisuitableheating element wire with the upper end of the, helix led off downthrough asuflicient openingin the upper end of-the inner form asillustrated in Figure 6, and with the lower end of. the'helix' led offinto the interior of 'the inner form 26-as also illustratedin Figure 6,both of the resultant leads passing into the conduit l4 leadingto thecontrolbox;

The base 6, the inner form-26g and-theouter form 3t, are preferablyformed of fire-clay or other heat-holding; noncombustible material such,as Kast Set.

In theoperation of .thedevice-of the;invention,

the-current supply I8v is applied. through the con trol box [5. to theheating-element'llso as-tocause suchheating element through theresistance to passage of electricity therethrough .to attain hightemperature and-thereby heat the inner form 26, the-space 32 between theinner andouter forms, and the outer form '31- and the base fi so thatthe inner and outer forms and the base may'become' a cherryred orapproach incandescence, or

otherwise exhibit a required temperature for the space to be heated.When the desired or set temperature is reached, the thermostatic controlI5 is operated by its bulb ll so as to cut ofi the energizing currentuntil such time as the temperature of the heating device falls andre-energization of the heating element I3 is required to restore ormaintain the desired or set temperature.

. Although I have shown and described herein preferred embodiments of,my invention, it is to be definitely understood that I do not wish tolimit the application of my invention thereto, ex-

cept as may be required by the scope of the subjoined claim.

Having described the invention what is claimed as new is:

A'heating; device comprising a circular base composed of a plurality oftriangular-shaped segments having their apices cut off to provideopenings, and having'their opposite ends provided with tongues-andgrooves, respectively, formating with the I tongues and grooves ofthe:ad-.

jacent segments, one of said; segments having an orifice therein, aninner hollow formyrising from: said base, an outer hollowform-risingfrom said base concentrically around and spacedly en--closing, said inner form, said inner and outer.-

forms being ofheat-holding; non-combustible material and being-formedvofsegments in edgee to-edge relation, the lower edgesof the segmentscomprising at least one of said forms andthe top of the base beingformed with companion. tongues and grooves. to provide-separable rigid:zconnection of the assembled segments of. the

forms and the base, a helical heating element spirally wound on theinner form andhaving the wires leading from its opposite ends passedthrough the'orifice in the-one segment: of the base,- athermostatic bulbmounted in the open ing provided in the apex portion ofthe segments;

and an; electric control box connected to the wires leading from thehelical heatingelement and connected to the thermostatic bulb.

WILLIAM- H. HEARD.

